Thinking Scientifically

1. Describe the relationships that connect:

     a. roots and mycorrhizal fungi

     b. leaf-cutter ants, their fungal food, bacterial symbionts, and pathogenic fungi

2. Penicillin, an antibiotic derived from a fungus, kills certain bacteria by destroying their cell walls. Why doesn’t penicillin harm fungal cell walls?

3. Describe how experiments showed that:

     a. Chytrids are killing amphibians.

     b. Fungi benefit more from a lichen relationship than do algae.

     c. Bacteria help leaf-cutting ants cultivate one fungus from killing another.

4. What are the two functions of spores?

Additional Questions

1. Some crop plants have been genetically altered to express a gene that encodes endochitinase which degrades chitin. The goal is to have the enzyme function as a built-in protection against fungal infection. How could this plan backfire, harming the plants?

2. Compare and contrast the actions of Pilobolus and chytrids in a cow’s stomach.

3. Why, technically, should a mushroom pizza not be considered a vegetable pizza?

4. To study the reproduction of Coccidioides immitis, the fungus that causes Valley Fever, researchers examined 14 DNA sequences in fungal cells taken from 25 people with the illness. Each patient had a unique combination of the 25 DNA regions. Does this indicate that the fungus reproduces asexually or sexually? Cite a reason for your answer.

5. Why might classification of a fungus as a deuteromycete reflect human limitations and prejudices rather than evolutionary relationships?